1. Field of the Invention
The present Invention is in the field of telephony communications and pertains more particularly to methods and apparatus for creating telephony switching type functionality on an Internet Protocol (IP) network in a distributive fashion.
2. Discussion of the State of the Art
The field of telephony communication has undergone revolutionary improvement with the addition of computer integration by way of telephony-switch-connected digital processors running software applications designed to improve call processing and switching intelligence within a communication center and in some cases, within a communications network Such integration of telephony equipment and computer-processing equipment is known in the art as computer-telephony-integration (CTI), and is well known and widely available in various forms. Communications centers, as described above, are generally integrated with a connection-orientated-switched-telephony (COST) network such as a public-switch-telephone-network (PSTN) as is known in the art. In some cases, there are multiple centers interconnected via a wide-area-network WAN as known in the art.
In typical application, a communication center is enhanced with a CTI processor and software adapted to be connected to a communication-center COST switch, such as a PBX (central switch) within or local to the communication center for the purpose of improving intelligence to the COST switch by virtue of added software. In some embodiments known to the inventor, CTI capability is also added to telephony switches within a COST network such as to a service-control-point (SCP). CTI processors (network level and communication center processors) are connected together by a digital link so that certain CTI functions implemented at an SCP may be controlled from within a communication center (known to inventor). In this way intelligent routing, and other CTI functions may be initiated at network level and communication efficiency may be generally improved.
Data-network-telephony (DNT) communication has recently been developed for the purpose of allowing voice/video calls to be placed over a packet data network. A sub-set of DNT known as Internet-protocol-network-telephony (IPNT) is the most successful and widely implemented format practiced on data networks such as the well known Internet. Communication center capabilities have been further improved via implementation of local area network (LAN) capability, addition of communication equipment such as LAN-connected personal computer/video display units (PC/VDU's) with software to implement IP-telephony, and so on.
Agents or other users working in such a CTI-enhanced communication center, or in a large organization hosting multiple communications centers, no longer simply answer switch-connected telephones. Access to IP networks have enabled communication centers and multi-center sites to utilize PC/VDU's and other digital apparatus to send and receive e-mails and voice calls/messages in data-network-telephony (DNT) format.
Communication centers have more recently incorporated IPNT technologies into their COST infrastructure. Hence, IP calls as they are termed in the art, may be placed and received in much the same way as COST calls. In a typical scenario, data-router gateways (nodes) are set-up in an IP network for point-to-point connection between nodes. Nodes local to communications centers are connected to telephony switches (usually a PBX) at respective communication centers. Typically, such IP technology only replaces switch-to-switch telephony trunking in this scenario.
In true IP telephony, as known to the inventor, traditional COST switches at communications centers are replaced by IP-capable switches. Cost functions, such as some PBX features, are emulated at IP switches by incorporating CTI software to provide intelligent network (IN) functionality. A problem with this approach, however, is that some PBX functions cannot be economically practiced with IP telephony. For example, if an IP call is placed from one site to a second site, and the user at the second site is having his calls forwarded to a third party at the first site, then the call must travel two times across the link. This is due to current art requirements in DNT for setting up each instance of connection from source to final destination each time a connection is needed. Because IP telephony uses shared bandwidth as opposed to having a COST dedicated connection, capacity is wasted with multiple channel establishment, and quality of service (QoS) associated with IP calls over the connection may be degraded if there are many such calls. This is true in a COST integrated IP network, as well as in an IN (true IP).
What is clearly needed is a method and apparatus that will emulate PBX, or other standard COST-switch functions and features on an IP network, including connected communication centers, with minimal degradation of QoS or using up otherwise available resources.